Net Loss per Share - Computation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ (125,551)	$ (66,150)	$ (77,187)
Denominator:
Weighted-average shares used to compute net loss per common share, basic and diluted	46,322,910	34,396,446	25,894,024
Net loss per shares, basic and diluted	$ (2.71)	$ (1.92)	$ (2.98)